Jet-operated air compressor



Patented Dec. 13, 192 7 UNITED STATES PATENT OFFICE.

GEORGE MQKERAHAN, or ALrooNA, PENNSYLVANIA.

' ur ornnnrinn AIR ooivrransson.

Application filed April 6,

The invention is an improvement' in the jet operated air compressor foi*-whichLet- .ters Patent No. 1,469,864 were issued to this applicant on October 2d 1923, and which comprises a revolving air wheelhaving air chambers placed concentrally and lengthw se of the wheels ax s; and et nozzles disposed at" one end of the air wheel so as :to discharge fluid pistons. into the open ends angle, formed with the wheels axis, gradually increases from the jet end to the discharge end of the air wheel, and the object of the invention is to make the helix angleconform .Jtothe gradual reductionof velocity ofthe fluid pistonsas these pass through the air chambers.

The drawings illustrate theapplication of the improvement to a design in which the 'air wheel closely fits and rotates within a stationary casing, but it is equally applicable to the construction shown in Fig. of the aforementioned Letters Patent where the casing tightly fits and revolves with the wheel.

In the accompanying drawings Fig. 1 shows a central section through the jet nozzles, air wheel casing and discharge pipe; a full side view of the air wheel within its casing is exposed. Fig. 2 is a section on the line 22 of Fig. 1, being a transverse section through the jet nozzles and the lower journal of the air wheel; this figure also shows an end View of the air wheel chant hers and wheel casing. Figs. 3'and 4 are diagrams which more clearly show the nature of the improvement.

In the illustration Fig. 1 the helically chambered air. wheel 1 is disposed vertically and the chamber walls 2 form two sides of the air chambers 3,. the chambers being .closed on the circumferential side of the wheel by the stationary casing 4 in which the air wheelhas a. close running fit. The lower end of the wheel has a journal 5 which r0 tates in bearing 6. :A hearing collar 7 sup ports the weight of the air wheel and 8 is a 1926. Serial No. 100,090.

cup for lubricant- In the construction shown bearing 6. is made integral with the two jet nozzles 9. The nozzlestructure supports the wheel casing-"'4 on lugs 10 by which the casing is fastened to the nozzles. A common supply pipe 11 conducts thejet fluid to nozzles 9.

Pipe 11 will connect with the discharge pipe of the jet pump, which is not shown, or with any other source which supplies the jet fluid at the required velocity.. The upper or discharge end of air. wheel 1 has a journal 12 which rotates in bearing 13, this hearing being secured to theiinterior of discharge pipe 14 by means of the radial ribs 15.; The outer end 16 of the discharge pipe will connectwitha separator or vessel in which the comprest air or other gas isseparated from the jet fluid, the separator not being shown inthe drawing.

The nature of the present invention will be more clearly understood by comparing the two diagrams, Figs. 3 and 4. On' areducejd scale these diagrams represent the outer surface of air wheel 1 when 'thelatter is developed or unrolled toa plane surface.-

Only a singleairchamber is shown on" each diagram as these Wlll suffice for illustrationp 'Fig. 4' shows an air chamber 17 1 of which the helix angle is constant from the jet end to the discharge end of the wheel,

the. direction of the chamber being a straight slope. Fig. 3 shows my improved air chamber. When the air wheel surface is unrolled flat the improved chamber 3 appears as a curve which has a gradually'increasing helix angle with the axis 18 of the air wheel.

The following explanation will make clear the important and useful effect of this improvement I p In this compressor the best efficiency will be obtained when the detached fluid pistons being affected by the revolving motion of the air chambers. The air compression is virtually completed before discharge from the air wheel and consequently the velocity of the fluid pistons will be, gradually reduced toward the discharge end of the wheel as a result of the accumulating resist ance of the air compression; and .as the initial 01' entering velocity of the fluid pistons,

because of their much greater velocity and.

energy at this stage will largely determine the rotating speed of the air wheel it follows that the pistons, toward the discharge end,

because of their reduced Velocity, will parpass straight through the air wheel without of the 'tluid pistons.

take somewhat of the revolving motion of the air ehan'ibers unless the helix angle is increased so as to malce the helical lead of the chanil' ers agree with the lower elocit-y Besides entailing a waete'tul and in jurious driving load upon the entering pistons a yet more serious etleet of even a small are of rerohition by the. pistons will he the generation, toward the discharge end of the wheel, of centrifugal action which will throw the pistons toward the circumference of the wheel and away from the bottom of the air chambers and creating at the latter place an open vent through which the comprest air will escape backward.

These large deductions from etlicieney will be entirely avoided by gradually increasing the helix angle of the air chambers toward the discharge end of the air wheel as already explained. An incidental benetit will be a gradual drawing together of air chamber wallsil. owing to their reduced helical lead, and thus etl'ectina' a gradual reduction of the chan'ibers cross area without tapering the outside diameter of the air wheel or reducing the radial depth of the chambers; this reduction of cross area will. insure a close lit oi the .tluid pistons as these advance towardtlie discharge end of the wheel.

The improvement will be especially useful in the case of liquid jets.

It may be stated that whenthe air wheel is rotated by a pulleyor other means con nected to an extension of the wheel shaft, the speed of the wheel in this case will be lluid sullicient to eon'iplctely tilltheehmm' ber seross area will be discharged into each air chamber as it passes across the jet.

The drawings show two jet nozzleswbut one nozzle or more than two may be used as required.

This compressor is suited for compression of other gases besides air and it may be used as aacuum pump or exhauster if. the

necessary connections are made.

WVhat I claim is:

In a jet operated air compressor tubular air chambersdisposed helically about a een tral shaft on which the wheel is rotated, and

the helix angle, formed bysaid airehambera with the axis of the wheel, being gradually increased "from the jet end tothediseharge end of the air wheel; jet nozzles adapted and disposed to discharge a fluid piston which will completely fill the cross area oi. each air chanibei as the open ends offthe chambers successively revolve into align ment with the nozzles; and means .at'the opposite end of the air chamber wheel for receiving the chambers.

GEORGEMCKERAHANJ discharge from the Wil'lCUl 

